【作者】 李波；

【导师】 袁永；

【作者基本信息】 中国矿业大学 ， 采矿工程， 2016， 硕士

【摘要】 大采高综采采场采高大,覆岩破坏高度大,顶板可能存在直接顶关键层,而直接顶关键层的存在对大采高工作面覆岩运动规律、采场位移应力分布、直接顶关键块稳定性、工作面支架工作阻力及矿山压力显现产生何种影响研究较少。故本文主要结合寺家庄矿15104大采高直接顶关键层综采工作面开采条件,运用理论分析、数值模拟、现场实践等研究方法,对大采高综采采场直接顶关键层破断结构特征与稳定性进行研究,主要得到以下研究成果:(1)研究了大采高直接顶关键层位置判别方法及周期破断形式。根据直接顶关键层工作面上覆岩层不同垮落形态划分为不规整垮落带、规则垮落带、裂隙带和弯曲下沉带“四带”,并给出了直接顶关键层位置判别方法及直接顶关键块以“砌体梁”和“悬臂梁”两种周期破断形式的理论判别式。(2)建立了大采高有无直接顶关键层数值计算模型,研究有无直接顶关键层上覆岩层运动规律、采场应力位移规律以及直接顶关键层层位、块度和硬度对工作面超前支承压力分布的影响规律。(3)建立了直接顶关键块初次破断力学模型,给出了直接顶关键块初次破断滑落失稳和回转失稳的理论判别式;根据直接顶关键块“悬臂梁”周期破断回转过程中能否触及已破断块体形成暂时稳定结构,建立了两种不同运动形式的计算模型,给出了回转过程中能触及已断块体的滑落失稳和回转失稳的理论判别式及回转过程中不能触及已断块体的滑落失稳理论判别式;分析了直接顶关键层和老顶关键层复合破断的影响因素,及出现工作面大小周期来压显现的原因。(4)建立了下位直接顶关键层“悬臂梁”-老顶“砌体梁”结构滑落失稳和回转失稳的计算模型,给出了滑落失稳和回转失稳产生冲击载荷时支架合理工作阻力的计算公式,并分析了工作阻力与各影响因素的关系;建立了上位直接顶关键层“砌体梁”-老顶“砌体梁”结构计算模型,给出了支架合理工作阻力的计算公式。(5)实测得到寺家庄15104直接顶关键层工作面初次来压步距37m,周期来压步距17m,工作面周期来压步距大致相等,不存在大小周期来压,且工作面周期来压持续长度平均达到4.1m,持续时间较长,证实了15104工作面直接顶关键层位于直接顶下部且以“悬臂梁”形式周期性破断。更多还原

【Abstract】 The roof of large mining height fully-mechanized working face is likely to have key immediate roof due to large working height and overburden damage height. The research on effect of key immediate stratum on overlying strata movement law, displacement and stress distribution of working face, key immediate block stability, support resistance and pressure behavior is less now. Based on geological conditions of 15104 large mining height fully-mechanized working face of Shijiazhuang Mine with key stratum, this paper studies overlying strata movement law and surrounding rock controlling techniques systematically using theoretical analysis, numerical simulation and field test. The thesis obtained the following results:(1)Study structural characteristics of overburden of large height key immediate stratum. Overlying layers of working face are divided into four zones: irregular caving zone, regular caving zone, fractured zone and curve subsidence zone. Theory criterion of periodical breaking motion in the type of voussoir beam and cantilever beam are also provided.(2)Establish numerical models of large height key immediate stratum and study overlying strata movement law, stress and displacement distribution law and effect of horizon, blockness and hardness of key immediate stratum on advanced abutment pressure distribution law.(3)Establish initially broken mechanical model of key block of immediate roof, Theory criterion of initially broken slide instability and rotational instability is presented. According to temporary stable structure forming in the process of periodical broken rotation of immediate roof voussoir beam, two different calculated model of motion are established. Theory criterion of slide instability and rotational instability reaching broken blocks and without reaching broken blocks. It also analyzes influencing factors of complex breakage of key immediate stratum and main key stratum and the reasons for large and light periodical weight behavior.(4)Establish calculating models of slide instability and rotational instability for low cantilever beam of key layer of immediate roof and voussoir beam of mian roof. Computing formula of reasonable working resistance of slide instability and rotational instability for i MPact loading is presented and factors influencing support resistance is analyzed. Establish calculating models of voussoir beam of key layer of immediate roof and voussoir beam of mian roof and show computing formula of reasonable working resistance.(5)The initial weighting distance of 15104 face measured in Sijiazhuang Mine is 37 m and periodical weighting distance is 17 m and basically identical always without large or little periodical weighting distance, remaining distance is 4.1m on average, which verified the horizon of key stratum of 15104 working face is lied under immediate roof and break in the type of voussoir beam periodically.更多还原